RustyNES

A Nintendo Entertainment System (NES) emulator written in Rust, currently focused on CPU emulation.

The 6502 CPU core implements the official instruction set and all addressing modes, enough to run a first program: the classic Snake demo, rendered with SDL3. The project is an ongoing exploration of instruction execution, memory access and the inner workings of a classic gaming system.

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How to run

Requirements

• Rust 1.80 or newer
• SDL3 available on your system (see the sdl3 crate docs for installation and build-from-source options)

Run

git clone https://github.com/jpedrosmenezes/RustyNES.git
cd RustyNES
cargo run --release

This launches the Snake demo.

Key	Action
W A S D	Move
Esc	Quit

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Project structure

src/
├── main.rs      # SDL3 frontend and Snake demo runner
├── cpu.rs       # 6502 CPU: registers, flags, addressing modes, instructions
└── opcodes.rs   # Opcode table (mnemonic, length, cycles, addressing mode)

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Credits

For learning how to build this I used the information/code/insights from:

• Writing NES Emulator in Rust: base structure and the Snake demo program
• 6502 Instruction Set
• NES Emulator From Scratch
• Emulation Online: Nintendo® Entertainment System (NES)

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Development Progress

• CPU official instruction set
• Memory addressing modes
• First program execution milestone (Snake demo)
• CPU validation with nestest
• Interrupts (BRK, NMI, IRQ)
• Cycle counting
• Unofficial opcodes
• Bus emulation
• Cartridge support (iNES, mappers)
• Picture Processing Unit (PPU)
• Joypad input
• PPU scrolling
• Audio Processing Unit (APU)

This project is under active development. The checklist reflects the current implementation status and will be updated as new components are completed.

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License

This project is licensed under the MIT License. See the LICENSE file for details.